Search for dissertations about: "metallicity"

Showing result 11 - 15 of 25 swedish dissertations containing the word metallicity.

  2. 11. Stochastic Chemical Evolution : A Study of Scatter in Relative Elemental Abundances in Extremely Metal-poor Stars

    Author : Torgny Karlsson; Bengt Gustafsson; Mike Edmunds; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; nucleosynthesis; chemical evolution; Galactic evolution; supernovae; chemical abundances; Population II stars; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik;

    Abstract : Chemical evolution addresses the problem of the formation of the chemical elements and their evolution throughout the history of the universe. This thesis discusses in particular the chemical evolution in the young universe and what we may learn from the observations of the oldest stars. READ MORE

  4. 12. Studies of Interstellar Molecular Gas in the Magellanic Clouds

    Author : Arto Heikkilä; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; abundances-Galaxies; evolution; molecules-Galaxies; Magellanic Clouds-Interstellar medium; molecules-Galaxies; interstellar medium-Galaxies;

    Abstract : Results of observational studies of interstellar molecular gas clouds in the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), two nearby metal-poor and dust-poor dwarf galaxies, are presented. Spectral line radiation emitted by interstellar molecules has been used to probe the physical state and the chemical composition of individual molecular clouds. READ MORE

  5. 13. Galactic Structure Revealed by Space Astrometry

    Author : Johan Holmberg; Astronomi - Genomgår omorganisation; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomi; cosmic chemistry; Galactic structure; Milky Way Galaxy; Galactic kinematics and dynamics; Galactic chemical evolution; moving groups; solar neighbourhood; dark matter; astrometry; Hipparcos; space research; Astronomy; rymdvetenskap; kosmisk kemi; Space technology; Rymdteknik; Fysicumarkivet A:2001:Holmberg;

    Abstract : This work demonstrates how the structure of our Galaxy, the Milky Way, can be unveiled with the use of space astrometry. It consists of two parts, of which the first is a brief introduction to the fields of Galactic structure, covering the Galaxy's stellar constituents, how the Galaxy was formed and how it has evolved over time, both chemically and kinematically. READ MORE

  6. 14. Stellar Ages for Galactic Archaeology : Methods and Applications

    Author : Christian Sahlholdt; Astronomi - Genomgår omorganisation; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Galaxy : formation; Stellar ages; Milky Way Galaxy; Low mass stars; Galaxy : disc; Galaxy : evolution; Fysicumarkivet A:2021:Sahlholdt;

    Abstract : Galactic Archaeology is the study of the formation and evolution of the Milky Way through the properties of stars and stellar populations. The combination of stellar ages, chemical compositions, positions, and velocities can reveal the history of star formation and chemical enrichment in different regions of the Galaxy. READ MORE

  7. 15. Solar Type Stars as Calibrators : A Photometric and Spectroscopic Study on the Atmospheric Properties of Late-type Stars

    Author : Anna Önehag; Ulrike Heiter; Andreas Korn; Bengt Gustafsson; Frank Grundahl; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; stars: atmospheres; stars: late-type; techniques: photometric; stars: abundances; techniques: spectroscopic; Astronomy; Astronomi;

    Abstract : Detailed knowledge of solar-type stars is essential in the understanding of the evolutionary past, presence and future of the Sun as well as the formation of its planetary system. Moreover, solar-type stars are of key significance for the study of the evolution of the Galaxy. The ages of solar-type stars map the full galactic evolution. READ MORE